<nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#">❤</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" datatarget="#
    navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" arialabel="
    Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
        <ul class="navbar-nav mr-auto">
            <li class="nav-item active">
                <a class="nav-link" href="#">主页 <span class="sr-only">(current)
                    </span></a>
            </li>
        </ul>
        <a class="btn btn-outline-success" [routerLink]="['/login']">登录</a>
    </div>
</nav>